To obtain a direct-current circuit breaker capable of reducing the current interruption burden and reducing the size and cost of the devices. A direct-current circuit breaker includes a switching unit 2 inserted in the direct-current line 1; and a commutation circuit 3 that includes a series circuit including a first current-limiting element 4 and an interrupting unit 5 that forms a current zero point by superimposing a resonance current on a direct current flowing in the direct-current line and interrupts the direct current at the current zero point, that is connected in parallel with the switching unit 2, and that becomes a flow path for the direct current after the switching unit 2 is opened, wherein current interruption is performed by the interrupting unit 5 after the switching unit 2 is opened.
